by Kim Hjelmgaard and Cathy Lynn Grossman, USA TODAY

by Kim Hjelmgaard and Cathy Lynn Grossman, USA TODAY

LONDON -- The United Kingdom's top cardinal, Keith O'Brien, is to step down as an archbishop, effective immediately, according to a statement published on the website of the Scottish Catholic news office.

Cardinal O'Brien, who is the leader of the Roman Catholic Church in Scotland and the U.K.'s most senior Roman Catholic, also says he is choosing not to take part in the election of the next pope next month to succeed Pope Benedict XVI, a process known as the "conclave.' He said in a statement that he will not attend.

His resignation came after news reports Monday of unspecified inappropriate behavior toward priests in the 1980s. He contests the allegations and pointed out in a statement that his request to resign was submitted to Benedict months ago. He said he would not attend the conclave because, "I do not wish media attention in Rome to be focused on me."

"Approaching the age of seventy-five and at times in indifferent health, I tendered my resignation as Archbishop of Saint Andrews and Edinburgh to Pope Benedict XVI some months ago. I was happy to know that he accepted my resignation 'nunc pro tunc' -- (now -- but to take affect later) on 12 November 2012," said Cardinal O'Brien, in the statement.

"I thank Pope Benedict XVI for his kindness and courtesy to me on my own behalf and on behalf of the people of Scotland, I wish him a long and happy retirement."

It is not yet clear if he has not resigned from the College of Cardinals. But the primary task of a cardinal is to vote in the conclave. In an interview with the BBC on Friday, before the news of his resignation, Cardinal O'Brien said he found the prospect of choosing the next pope "almost frightening."

Pope Benedict XVI's resignation takes effect on Thursday. And Monday, Benedict issued a letter spelling out line-by-line changes in canon law that will allow cardinals to set an earlier date for electing his successor. The number of eligible electors -- cardinals under the age of 80 -- is now 115.

However, there is growing pressure from U.S. victims of clergy sexual abuse for Cardinal Roger Mahony, the retired Archbishop of Los Angeles, to withdraw from the conclave. More than 30,000 pages of priest personnel records released last month revealed that Mahony had been directly involved in covering up for priests who were known to have abused children and teens.

Mahony has been writing on his personal blog that he plans to attend the conclave and to vote. There's precedent for that. Cardinal Bernard Law, who resigned from his post as Archbishop of Boston in 2002 at the height of the explosive abuse scandal, nonetheless voted in the 2005 election that chose Benedict.

Monday, Terence McKiernan, president of BishopAccountability.org, lauded O'Brien's recusal as an important precedent for a church where priests have been disciplined for abuse but church leaders who failed to halt the abuse have been largely unscathed.

"Cardinals who are tainted by the crisis cannot choose the person who will solve it,," .McKiernan said in a statement. "...If they are involved in the deliberations and the votes, they will taint the outcome, damaging the legitimacy of whoever is ultimately chosen."

The last time a cardinal resigned from the College of Cardinals was in 1927, says church historian Matthew Bunson. French Cardinal Louis Billot stepped down because his support for a radical, conservative political movement was in direct conflict with then-Pope Pius XI who opposed it.